JPH0971214A - Air bag device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid unnecessary operation of a supersonic sensor and relax the developing condition of an air bag device. SOLUTION: A supersonic sensor 44 for measuring the spatial distance in a seat back direction 14B from an air bag device 18 is arranged in front of an assistant seat 14 with its detecting direction pointed in the seat back 14B direction. Developing conditions of the air bag device 18 are set according to the distance measured by the supersonic sensor 44. Although the setting of the developing conditions is carried out by repetition to be renewed, it is carried out after lapse of time T depending upon whether the developing conditions are same as those fo the last time or not. Thereby, any unnecessary operation of the supersonic sensor 44 can be avoided. Meanwhile, the size of the air bag device 18 is controlled in accordance with the distance measured when the air bag device 18 is developed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air bag device for detecting a vehicle collision with an acceleration sensor to activate an inflator, and inflating a bag toward an occupant by gas ejected from the inflator.

[0002]

2. Description of the Related Art Conventionally, there is a vehicle such as an automobile equipped with an airbag device for protecting a seated occupant in a vehicle collision on the driver's seat side and the passenger's seat side.

The conventional airbag device is designed to be deployed when a vehicle collision is detected by an acceleration sensor attached to the vehicle. Whether the occupant is seated on a seat or not, and the airbag device. Therefore, the spatial distance in the seat back direction (deployment space of the airbag device) and the like were not taken into consideration, and the timing and capacity of deployment of the airbag device were always constant.

In order to solve this problem, the spatial distance in the seat back direction from the air bag device is detected by using an ultrasonic sensor, and a child restraint device is attached to determine whether or not the occupant is seated on the seat. There has been considered an airbag device capable of deploying the airbag device only when appropriate conditions are met by determining whether or not the condition is met. Thereby, the original function of the airbag device can be sufficiently exerted.

However, if ultrasonic waves are constantly transmitted from the ultrasonic sensor and are activated, the usable period of the ultrasonic sensor becomes short, so it is necessary to replace the ultrasonic sensor at a relatively early stage.

[0006]

In consideration of the above facts, the present invention is capable of avoiding unnecessary operation of an ultrasonic sensor used for measuring a clearance in the seat back direction from an airbag device. An object of the present invention is to obtain an airbag device that can relax the range of conditions for deploying a conventional airbag device.

[0007]

In order to achieve the above object, the invention according to claim 1 detects a vehicle collision with an acceleration sensor to activate an inflator, and a gas is ejected from the inflator. An airbag device for inflating a body toward an occupant, the measuring device being provided in front of a vehicle seat, the detection direction being directed toward a seatback direction of the seat, for measuring a spatial distance in the seatback direction. A deployment condition setting means for setting a deployment condition of the airbag device based on a measurement result of the measurement means, an updating means for repeatedly executing and updating the deployment condition setting means, and an air conditioner in the vehicle collision. And a control means for controlling the deployment of the airbag device based on the latest deployment conditions when the bag device is deployed.

According to the first aspect of the present invention, the space distance in the seat back direction from the airbag device is measured by the measuring means, and the deployment condition of the airbag device is set by the deployment condition setting means based on the measurement result. To do. These processes are repeatedly executed until the driver turns off the engine when driving the vehicle. Therefore, the deployment condition can be updated by the updating unit, and the deployment of the airbag device can be controlled by the control unit based on the latest deployment condition.

According to a second aspect of the present invention, the deployment condition setting means determines that the child restraint device is attached, the measurement means determines that the result is a close range, or If it is determined that the seat belt is not worn and the occupant is not seated, at least one of them is determined.
It is characterized in that the deployment prohibition of the airbag device is set as the deployment condition when the three conditions are met.

According to the second aspect of the invention, when at least one of the above conditions is met, the deployment condition setting means can control the airbag device to be prohibited from deployment.

According to a third aspect of the present invention, when the deployment condition setting means determines that the child restraint device is attached, or the result of the measuring means is determined to be a close range. It is characterized in that the expansion capacity of the bag body of the airbag device is controlled.

According to the third aspect of the present invention, the airbag device is prohibited from being deployed when the child restraint device is mounted or when the measurement result of the measuring means is determined to be a close range. In addition to the control, the deployment timing of the airbag device can be controlled, the deployment capacity can be reduced, and the airbag device can be deployed so that it can be deployed even outside the original deployment condition range.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An airbag device 18 according to an embodiment of the present invention will be described with reference to the drawings.

The arrow FR in the figure indicates the forward direction of the vehicle.
The arrow UP indicates the vehicle upward direction.

As shown in FIG. 1, the airbag device 18 according to the embodiment of the present invention is mounted in the passenger compartment 14 of the vehicle 10 in front of the passenger seat 14. An airbag device (not shown) is also mounted on the driver's seat side.

An instrument panel 16 is arranged in front of the passenger seat 14 in the vehicle, and an airbag device 18 for a passenger seat is provided on the back side of the instrument panel 16. The passenger airbag device 18 is elongated in the vehicle width direction, and a portion of the instrument panel 16 facing the passenger airbag device 18 is
The airbag cover 20 has a rectangular shape that is elongated in the vehicle width direction.

As shown in FIG. 2, the case 22 of the passenger seat airbag device 18 in the vehicle interior 12 of the vehicle 10 has a substantially U-shaped cross section as viewed in the vehicle width direction. An opening 24 is formed in the case 22 obliquely upward and rearward of the vehicle. An opening edge of the airbag body 26 is fixed to the inner periphery of the opening 24.

A cylindrical inflator 34 is arranged in the case 22 in the vicinity of the bottom portion 22A along the vehicle width direction. The inflator 34 is filled with a gas generating substance, and the inflator 34 is activated when an acceleration sensor 41 described later detects a vehicle collision.
By ejecting gas from the inflator 34,
Gas is filled in the airbag bag body 26 stored in a folded state near the opening 24 of the case 22, and the airbag bag body 26 is inflated, so that the instrument panel 16
The airbag cover portion 20 is broken and deployed in the vehicle interior 12. Accordingly, the occupant 54 can be protected in the event of a vehicle collision.

Further, when the airbag device 18 is deployed, the airbag bag body 26 is provided in accordance with the distance between the airbag device 18 and the occupant 54 so that the function of protecting the occupant 54 can be sufficiently exerted. The size of is controlled. Therefore, a plurality of airbag bags 26 having different sizes are provided in the case 22.

The inflator 34 is connected to a control circuit 41 arranged below the back side of the instrument panel 16. Also, this control circuit 4
An acceleration sensor 41 is connected to 1. The acceleration sensor 41 outputs a signal for operating the inflator 34 to the control circuit 40 when the vehicle 10 rapidly decelerates by a predetermined value or more.

Further, the control circuit 40 is connected with an ultrasonic sensor 44 as a distance measuring means for measuring the spatial distance from the airbag device 18 in the seat back 14B direction. The ultrasonic sensor 44 is provided on the instrument panel 18 with the detection direction of the seatback 14B.
It is arranged in the direction. This ultrasonic sensor 44
Transmits ultrasonic waves based on an instruction from the control circuit 40, receives the reflected waves, calculates the spatial distance from the transmission time and the reception time, and inputs the spatial distance to the control circuit 41. Air bag body 26 that expands according to this space distance
The size of is controlled. In addition, if the result of whether or not to deploy the airbag device is the same as the previous time, the transmission of the ultrasonic wave from the ultrasonic sensor 44 is performed at the time T.
After a lapse of time, the process is performed again, and when the result is different from the previous result, the process is performed immediately, and in any case, the process is repeated. As a result, it is not necessary to constantly transmit the ultrasonic wave from the ultrasonic sensor 44 (it does not operate during the time T).
The usable period of the ultrasonic sensor 44 becomes longer.

A seat belt retractor 48 is disposed below the center pillar 46, and the seat belt 5
0 is accommodated so that it can be pulled out and wound up. The seat belt retractor 48 is switchable between an automatic locking type winding state (ALR) and an emergency locking type winding state (ELR), and when the passenger 54 is seated in the passenger seat 14, the seat belt retractor 48 is seated. The ELR is used to pull out the belt 50 from all the winding positions by a predetermined amount (other than the total pulling-out position) to be mounted. In addition, as shown in FIG.
If the child seat 56 for holding 5 is fixed by the seat belt 50, the seat belt 5
The child seat 56 is securely held by setting 0 to the fully withdrawn state and then switching to ALR. In addition, the child seat 56 is removed, and the seat belt 5
By setting 0 to the fully wound state, the mode is switched to ELR again. Furthermore, the seat belt retractor 48 is an ALR.
And a winding state detection switch 52 which is interlocked with switching between ELR and ELR. The winding state detection switch 52 is
It is connected to the control circuit 40 and inputs to the control circuit 40 whether the seat belt retractor 48 is in the ALR or ELR state. Based on the state of the winding state detection switch 52, it is determined whether or not the child seat 56 is mounted on the passenger seat 14.

As shown in FIGS. 2 and 3, the buckle 58 of the seat belt 50 has a seat belt switch 5
9 are provided. This seat belt switch 59
Is engaged when the tongue plate 60 is engaged with the buckle 58. The seat belt switch 59 is also connected to the control circuit 40,
Whether the tongue plate 60 is engaged with the buckle 58, that is, the usage state of the seat belt 50 is input to the control circuit 40. When the tongue plate 60 is engaged with the buckle 58, that is, when the seat belt switch 59 is on, it is determined that the occupant 54 seated on the passenger seat 14 is wearing the seat belt 50. Will be.

Whether or not the child seat 56 is attached by the winding state detection switch 52 described above, the ultrasonic sensor 4
4 according to the measurement result of the spatial distance between the airbag device 18 and the seat back 14B by 4 and the wearing state of the seat belt 50 by the seat belt switch 59.
8 is controlled to be prohibited from being expanded or allowed to be expanded, and an airbag device deployment condition for controlling the size of the airbag bag 26 is set.

Next, the operation of the embodiment of the present invention will be described with reference to the flowchart of FIG. Each process of the flowchart shown in FIG. 4 is repeatedly executed when the vehicle 10 is driven until the driver turns off the engine.

As shown in this flow chart, according to the airbag device 18 according to the embodiment of the present invention,
The control circuit 40 performs self-diagnosis in step 100, and further performs initialization in step 102.

Subsequently, at step 104, it is judged whether or not the child seat 56 is mounted on the passenger seat 14. This is because when the winding state detection switch 52 detects that the seat belt retractor 48 is in the automatic locking type winding state (ALR), the child seat 56 is fixed on the passenger seat 14 via the seat belt 50. It is determined that If it is determined that the child seat 56 is attached in this manner, step 10
6, the airbag device 18 is controlled so as not to be deployed.

On the other hand, if it is determined in step 104 that the child seat 56 is not mounted on the passenger seat 14, the process proceeds to step 108, and the airbag device 18 is moved.
To measure the spatial distance in the direction of the seat back 14B. An ultrasonic sensor 44 is used to measure this distance. Ultrasonic waves are transmitted from the ultrasonic sensor 44 toward the seat back 14B, the reflected waves are received, and the spatial distance (L shown in FIG. 2) is calculated from the transmission time and the reception time in step 110. In addition, the passenger 5 on the passenger seat 14
When there is no 4, the distance from the airbag device 18 to the seat back 14B is calculated.

Based on the distance thus obtained, the position at which the occupant 54 is extremely close to the passenger airbag device 18,
That is, it is determined whether or not it is within a close range. If it is determined that the vehicle is in the close range, the process proceeds to step 114 and the deployment of the airbag device 18 is prohibited. The expansion condition mode at this time is set to 0.

On the other hand, if it is determined in step 108 that the occupant 54 is not in the close range, step 1
Move to 16. In this step 116, in order to control the size when deploying the airbag device 18 according to the spatial distance from the airbag device 18 in the direction of the seat back 14B (distance measured and calculated in steps 108 and 110). Set the conditions of.

In the embodiment of the present invention, this is divided into three cases as shown below.

First, when it is determined that the occupant 54 is not at the closest distance but at a position close to the airbag device 18 (FIG. 5A), that is, when the measured spatial distance is short, the deployment condition mode is set. Is set to 1 and the airbag bag body 26
The expansion is controlled so that the size becomes 80 to 100 cm. In addition, a position far from the airbag device 18 (see FIG.
(C)), the deployment condition mode is set to 3 and the size of the airbag bag 26 is 180c.
Expand so that it is more than m. When it is determined that the occupant 54 is in the intermediate position (FIG. 5 (B)), the deployment condition mode is set to 2 and the airbag bag is set to 120-
The expansion is controlled so that the size is 180 cm. In this way, a plurality of expansion condition modes are set according to the distances measured and calculated in steps 108 and 110 (see Table 1).

[Table 1]

Further, it is determined whether or not the occupant 54 is wearing the seat belt 50 on the passenger seat 14.
This is determined by detecting the on / off state of the seat belt switch 59. If the seat belt switch 59 is in the ON state, the seat belt 50
Is determined to have been installed. If it is determined that the seat belt 50 is worn, step 1
24, the airbag device 18 is to be deployed based on the set deployment condition mode.

On the other hand, if it is determined that the seat belt 50 is not worn, the amount of change in the distance obtained in step 110 is detected. The process of this flowchart is repeatedly executed until the engine is turned off.
Therefore, the amount of change in distance indicates the difference between the spatial distance measured in the direction of the seat back 14B from the airbag device 18 measured this time and the previous spatial distance measured by the same method.
Based on this change amount, in step 122, the occupant 5
4 determines whether or not 4 is seated in the passenger seat 14. When the measured distance is changed, it is determined that the occupant is seated. In this case, the airbag device 18 is to be deployed based on the deployment conditions set in step 116 described above.

On the other hand, when it is determined that the occupant 54 is not seated because there is no change in the measured distance, the airbag device 1
Controls 8 to prohibit expansion.

Subsequently, in step 128, it is determined whether the final result of the airbag device 18 is prohibition of deployment (step 106, step 114, step 126) or permission of deployment (step 124). It is determined whether the result is the same as the determination result of this processing. If it is determined that the results are not the same, the process returns to step 104 and the same processing is repeatedly executed. If the determination results are the same, step 130
After a lapse of time T, the process returns to step 104 and the same process is repeated again. Here, the reason why the process is repeated after the time T has elapsed is that it can be predicted that the state will continue for a while when it is determined that the same result is obtained. In the embodiment of the present invention, the time T is about 2 seconds. In this way, the process is repeated after the lapse of time T in some cases, so that it is not necessary to constantly transmit the sensor from the ultrasonic sensor 44,
The ultrasonic sensor 44 can be made to last longer.

Therefore, the airbag device 18 according to the embodiment of the present invention has the child seat 56 on the passenger seat 14.
Is attached, the occupant 54 seated in the passenger seat 14 is at a short distance from the airbag device 18, and the seat belt 50 on the passenger seat 14 is not attached and the occupant is not seated. Since the inflator 34 does not operate even when a vehicle collision is detected, the airbag device 18 does not deploy. As a result, it is possible to reduce the possibility of replacing the passenger seat airbag device 18 after an accident (after using the airbag device) and reduce the repair cost. Further, when the occupant 54 is seated on the passenger seat 14, the spatial distance in the direction of the seat back 14B from the airbag device 18 is measured, and the airbags of different sizes are deployed according to the measured distance. Thus, the original function of the airbag device can be fully exerted.

In the embodiment of the present invention, the size of the airbag is changed by providing a plurality of airbag bags having different sizes.
The size of one airbag bag 26 may be controlled by changing the amount of the gas generating substance used according to the spatial distance from 8 to the seat back 14B.

Further, when the occupant 54 is close to the airbag device 18, or when the child seat 56 is mounted on the passenger seat 14, the airbag device 1
8 is controlled to be prohibited from being deployed. However, in some cases, the airbag device 18 is not completely prohibited from being deployed, but the airbag bag body 26 is provided so that the function of the airbag device 18 can be fully exerted. The expansion capacity may be reduced or the expansion timing may be advanced to control the expansion.

Further, in the embodiment of the present invention, the winding state detection switch 52 of the seat belt 50 is used to detect whether or not the child seat 56 is attached. However, whether or not the child seat 56 is attached is used. You may provide the mere switch which shows. This switch is set to ON when the occupant wears the child seat, and whether the child seat is mounted is detected by turning the switch ON / OFF.

Although the ultrasonic sensor 44 is used as the distance measuring means in the embodiment of the present invention, another distance detecting sensor such as an infrared sensor other than the thermal sensor is used instead of the ultrasonic sensor 44. Good. Further, an example in which the size of the airbag bag body 26 is controlled in three stages in accordance with the result of the measuring means has been described, but this is an example and not limited to three stages.

Further, in the embodiment of the present invention, the time T until the process is repeated is set to 2 seconds, but a means for controlling so as to change the time T according to the speed of the vehicle is provided. Good.

In the embodiment of the present invention, the example in which the airbag device of the present invention is used in the passenger seat has been described, but the present invention may be used in the rear seat, and further, the side airbag device. May be used as.

[0044]

As described above, the airbag apparatus of the present invention measures the spatial distance in the seat back direction from the airbag apparatus by the measuring means and sets the deployment condition mode according to the distance to deploy the airbag. By controlling the presence or absence of deployment of the airbag device and controlling the size of the airbag bag, there is an excellent effect that the original function of the airbag device can be fully exerted.

Further, there is an excellent effect that the usable period of the ultrasonic sensor can be lengthened by reducing the transmission time of the ultrasonic wave from the ultrasonic sensor.

[Brief description of drawings]

FIG. 1 is a perspective view of an instrument panel to which an airbag device according to an embodiment of the present invention is applied, as seen obliquely from the rear of the vehicle.

FIG. 2 is a schematic side view showing an airbag device according to an embodiment of the present invention.

FIG. 3 is a schematic side view showing a state in which a child seat (child restraint device) is mounted on a passenger seat to which the airbag device according to the embodiment of the present invention is applied. The dotted line portion in the figure shows a state in which the child seat is mounted in the direction opposite to the traveling direction of the vehicle.

FIG. 4 is a flowchart showing a control routine of the airbag device according to the embodiment of the present invention.

FIG. 5 is a side view showing a difference in angle of a seat back of a passenger seat.

[Explanation of symbols]

 14 Front passenger seat 16 Instrument panel 18 Front passenger seat airbag device 26 Air bag body 34 Inflator 40 Control circuit 41 Accelerometer 44 Ultrasonic sensor (distance measuring means) 48 Seat belt retractor 50 Seat belt 52 Winding state detection switch 54 Crew 56 Child seat (Child restraint) 59 Seatbelt switch

Claims (3)

[Claims] 1. An airbag device for detecting a vehicle collision with an acceleration sensor, activating an inflator, and inflating a bag toward an occupant by gas discharged from the inflator, the airbag device being provided in front of a vehicle seat. A measuring unit arranged so that the detection direction is directed toward the seat back direction of the seat, and measuring means for measuring a spatial distance in the seat back direction, and deployment for setting deployment conditions of the airbag device based on a measurement result by the measuring means. Condition setting means, updating means for repeatedly executing and updating the setting of the deployment condition setting means, and controlling deployment of the airbag device based on the latest deployment condition in a situation where the airbag device is deployed due to the vehicle collision And an air bag device having: 2. The deployment condition setting means, when it is determined that the child restraint device is worn, when the result of the measuring means is determined to be a close range, or when the seat belt is not worn and the occupant is not. The airbag apparatus according to claim 1, wherein, when it is determined that the vehicle is not seated, deployment prohibition of the airbag apparatus is set as a deployment condition when at least one of these conditions is satisfied. 3. The bag body of the airbag device when the deployment condition setting means determines that the child restraint device is attached or when the result of the measurement means is determined to be a close range. The airbag device according to claim 1, wherein the deployment capacity is controlled.